The present invention relates to vehicle controlling apparatus and method for taking an evasive action to avoid collision with obstacles appropriately covering vehicle""s behaviors before and after the evasive action.
Several types of vehicle controlling apparatus have been developed and put into practical use for enhanced vehicle performance.
The followings are representatives of such vehicle controlling apparatus: a braking-force controller for appropriately applying braking force to wheels against any force exerted on a vehicle, for example, during cornering; a rear-wheel steering controller for controlling rear wheels in accordance with vehicle travelling conditions; a right-to-left torque-split controller for controlling torque split to right and left wheels in accordance with vehicle travelling conditions; and a torque-split controller for torque split between front and rear wheels by controlling differential power of a center differential between the front and rear wheels in accordance with vehicle travelling conditions.
Among other techniques also proposed recently is recognition of any obstacles in front, such as a vehicle travelling ahead, of a driver""s vehicle. Japanese Unexamined Patent Publication No. 7-21500, for example, discloses an automatic brake controller. In detail, a driver""s steering is always detected. When the driver""s vehicle and an obstacle are becoming close and it is determined that the driver""s vehicle cannot avoid collision with the obstacle only by usual braking control, the automatic brake controller controls braking force for each wheel for enhanced steering performance, or quick response to the driver""s steering.
The known apparatus achieves an appropriate control until the driver takes an evasive action, but not offering various fine controls after the evasive action.
Moreover, the known apparatus achieves high steering performance with automatic braking. It is, however, preferable that high steering performance is achieved by any vehicle controlling apparatus discussed above.
These vehicle controlling apparatus have to operate appropriately in accordance with complex operations such as evasive driving for avoiding an obstacle and then returning to the original position by a short time.
An evasive driving mode under control by such vehicle controlling apparatus has to be informed to a driver on screen or by an alarm. This is because the vehicle control characteristics will vary during the evasive driving mode. The driver could, however, not notice such information while taking an evasive action.
Such an evasive-driving system should have more effective way to inform a driver that a vehicle is going to enter the evasive driving mode and also whether the vehicle control characteristics is different from usual driving due to the evasive driving mode.
A purpose of the present invention is to provide vehicle controlling apparatus and method for an appropriate evasive action by accurately recognizing obstacles to a vehicle, precisely operating a controlling device for each vehicle behavior, and also effectively informing a driver of vehicle""s behaviors during the evasive action.
The present invention provides a vehicle controlling apparatus installed in a vehicle including: an obstacle recognizer to recognize an obstacle existing ahead of the vehicle for detecting information on the obstacle; a vehicle information detector to detect information on travelling conditions of the vehicle; a vehicle controller to change steering performance of the vehicle for controlling behaviors of the vehicle; an evasive-driving determiner to determine whether the vehicle can avoid collision with the obstacle only by a driver""s braking operation based on at least the information on the obstacle and the vehicle; an evasive-driving controller to control the vehicle controller to enter into an evasive driving mode in accordance with a driver""s steering operation and the vehicle behaviors when it is determined that the vehicle cannot avoid collision with the obstacle only by the driver""s braking operation and also control the vehicle controller to change a control operation of the vehicle controller in the evasive driving mode in accordance with the driver""s steering operation and the vehicle behaviors; a preliminary informer to give a preliminary information to the driver to indicate that the vehicle controller will enter into the evasive driving mode; and a final informer to inform the driver that the vehicle controller has entered into the evasive driving mode.
Moreover, the present invention provides a vehicle controlling method including the steps of: recognizing an obstacle existing ahead of a vehicle to detect information on the obstacle; detecting information on travelling conditions of the vehicle; changing steering performance of the vehicle for controlling behaviors of the vehicle; determining whether the vehicle can avoid collision with the obstacle only by a driver""s braking operation based on at least the information on the obstacle and the vehicle; entering into an evasive driving mode in accordance with a driver""s steering operation and the vehicle behaviors when it is determined that the vehicle cannot avoid collision with the obstacle only by the driver""s braking operation; changing the steering performance of the vehicle in the evasive driving mode in accordance with the driver""s steering operation and the vehicle behaviors; giving a preliminary information to the driver to indicate that the vehicle will enter into the evasive driving mode; and informing the driver that the vehicle has entered into the evasive driving mode.